// ========================================================================
// Copyright (c) 2009 Intalio, Inc.
// ------------------------------------------------------------------------
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// and Apache License v2.0 which accompanies this distribution.
// The Eclipse Public License is available at 
// http://www.eclipse.org/legal/epl-v10.html
// The Apache License v2.0 is available at
// http://www.opensource.org/licenses/apache2.0.php
// You may elect to redistribute this code under either of these licenses. 
// ========================================================================
package org.eclipse.jetty.osgi.boot.utils;

import java.io.File;
import java.net.URL;
import java.util.Enumeration;

import org.eclipse.jetty.osgi.boot.utils.internal.DefaultFileLocatorHelper;
import org.osgi.framework.Bundle;

/**
 * From a bundle to its location on the filesystem. Assumes the bundle is not a
 * jar.
 * 
 * @author hmalphettes
 */
public interface BundleFileLocatorHelper
{

    /** The name of the custom implementation for this interface in a fragment. */
    public static final String CLASS_NAME = "org.eclipse.jetty.osgi.boot.utils.FileLocatorHelperImpl";

    /** The default instance supports felix and equinox */
    public static BundleFileLocatorHelper DEFAULT = new DefaultFileLocatorHelper();


    /**
     * Works with equinox, felix, nuxeo and probably more. Not exactly in the
     * spirit of OSGi but quite necessary to support self-contained webapps and
     * other situations.
     * <p>
     * Currently only works with bundles that are not jar.
     * </p>
     * 
     * @param bundle
     *            The bundle
     * @return Its installation location as a file.
     * @throws Exception
     */
    public File getBundleInstallLocation(Bundle bundle) throws Exception;

    /**
     * Locate a file inside a bundle.
     * 
     * @param bundle
     * @param path
     * @return file object
     * @throws Exception
     */
    public File getFileInBundle(Bundle bundle, String path) throws Exception;

    /**
     * If the bundle is a jar, returns the jar. If the bundle is a folder, look
     * inside it and search for jars that it returns.
     * <p>
     * Good enough for our purpose (TldLocationsCache when it scans for tld
     * files inside jars alone. In fact we only support the second situation for
     * development purpose where the bundle was imported in pde and the classes
     * kept in a jar.
     * </p>
     * 
     * @param bundle
     * @return The jar(s) file that is either the bundle itself, either the jars
     *         embedded inside it.
     */
    public File[] locateJarsInsideBundle(Bundle bundle) throws Exception;
    
    
    /**
	 * Helper method equivalent to Bundle#getEntry(String entryPath) except that
	 * it searches for entries in the fragments by using the findEntries method.
	 * 
	 * @param bundle
	 * @param entryPath
	 * @return null or all the entries found for that path.
	 */
	public Enumeration<URL> findEntries(Bundle bundle, String entryPath);

}
